Synthesis and characterization of MWCNT/TiO2 /Au nanocomposite for photocatalytic and antimicrobial activity.

A novel combination of titanium oxide (TiO₂)/gold (Au)/multiwalled carbon nanotubes (MWCNTs) nanocomposite (NC) was synthesised by sol– gel method. MWCNT functionalisation by modified Hummers method. TiO₂ /Au nanoparticles (NPs) were synthesised by biological method using Terminalia chebula bark extract. MWCNT/TiO₂ /Au NC samples were characterised by X‐ray diffraction, ultraviolet–visible–diffuse reflectance spectra, microRaman, scanning electron microscopy and high‐resolution‐transmission electron microscopy analyses. The photocatalytic performance of the obtained for NC toward the decomposition of congo‐red and the antimicrobial activity for inhibition of Gram positive (Bacillus subtilis, Streptococcus pneumonia and Staphylococcus aureus), Gram negative (Shigella dysenderiae, Proteus vulgaris and Klebsiella pneumonia) and fungal strains have been evaluated and the results are compared with positive control ampicillin. The metal and metal–oxide NPs have a lower sorption capacity. The herbicidal bond to the tested CNTs by the combination of electron donor–acceptor interactions and hydrogen bonds. In particular, the dispersion of NC and control of sodium borohydride, it has more efficient effect on the photodegradation and antibacterial activity of positive control of ampicillin. The NC material has exhibited maximum photodegradation and antibacterial activity results of zone of inhibition when compared with control samples.Inspec keywords: nanocomposites, nanoparticles, titanium compounds, gold, multi‐wall carbon nanotubes, nanofabrication, sol‐gel processing, catalysis, photodissociation, antibacterial activity, microorganisms, X‐ray diffraction, reflectivity, Raman spectra, ultraviolet spectra, visible spectra, hydrogen bonds, scanning electron microscopy, transmission electron microscopy, dyes, sorption, nanobiotechnologyOther keywords: titanium oxide‐gold‐multiwalled carbon nanotubes nanocomposite, sol‐gel method, photocatalytic activity, antimicrobial activity, MWCNT functionalisation, modified Hummers method, nanoparticles, biological method, Terminalia chebula bark extract, X‐ray diffraction, ultraviolet‐visible‐diffuse reflectance spectra, microRaman spectra, scanning electron microscopy, high‐resolution‐transmission electron microscopy, congo‐red decomposition, Gram positive bacteria, Bacillus subtilis, Streptococcus pneumonia, Staphylococcus aureus, Shigella dysenderiae, Proteus vulgaris, Klebsiella pneumonia, fungal strains, Gram negative bacteria, sorption capacity, herbicidal bond, electron donor‐acceptor interactions, hydrogen bonds, sodium borohydride, photodegradation, metal‐oxide nanoparticles, C‐TiO₂ ‐Au     

Antibacterial and anticancer activity of biosynthesised CuO nanoparticles

The present investigation aims for the synthesis of copper oxide nanoparticles (CuO NPs) using Nilgirianthus ciliatus plant extract. The obtained CuO NPs were characterised by X‐ray diffraction, Fourier transform infrared spectrum, ultraviolet–visible spectroscopy, photoluminescence, scanning electron microscopy and transmission electron microscopy analysis. Significant bacterial activity was manifested by CuO nanoparticles against both Gram‐positive (Staphylococcus aureus and Staphylococcus mutans) and Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The synthesised CuO NPs have good cytotoxicity against both human breast cancer cell line (MCF‐7) and lung cancer cell line (A549) with minimum cytotoxic effect on normal L929 (fibroblast) cell lines.Inspec keywords: microorganisms, ultraviolet spectra, nanomedicine, transmission electron microscopy, visible spectra, cellular biophysics, antibacterial activity, nanoparticles, X‐ray diffraction, lung, copper compounds, cancer, toxicology, biomedical materials, scanning electron microscopy, photoluminescence, Fourier transform infrared spectraOther keywords: antibacterial activity, anticancer activity, biosynthesised CuO nanoparticles, copper oxide nanoparticles, Nilgirianthus ciliatus plant, X‐ray diffraction, infrared spectrum, ultraviolet–visible spectroscopy, transmission electron microscopy analysis, bacterial activity, Gram‐negative bacteria, synthesised CuO NPs, human breast cancer cell line, Staphylococcus aureus, Staphylococcus mutans, CuO     

Green biosynthesis,characterisation and antimicrobial activities of silver nanoparticles using fruit extract of Solanum viarum

Green synthesis of nanoparticles is considered an efficient method when compared with chemical and physical methods because of its bulk production, eco‐friendliness and low cost norms. The present study reports, for the first time, green synthesis of silver nanoparticles (AgNPs) at room temperature using Solanum viarum fruit extract. The visual appearance of brownish colour with an absorption band at 450 nm, as detected by ultraviolet‐visible spectrophotometer analysis, confirmed the formation of AgNPs. X‐ray diffraction confirmed the AgNPs to be crystalline with a face‐centred lattice. The transmission electron microscopy‐energy dispersive X‐ray spectroscopy image showed the AgNPs are poly‐dispersed and are mostly spherical and oval in shape with particle size ranging from 2 to 40 nm. Furthermore, Fourier transform‐infrared spectra of the synthesised AgNPs confirmed the presence of phytoconstituents as a capping agent. The antimicrobial activity study showed that the AgNPs exhibited high microbial activity against Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus susp. aureus, Aspergillus niger, and Candida albicans. The highest antimicrobial activity of AgNPs synthesised by S. viarum fruit extract was observed in P. aeruginosa, S. aureus susp. aureus and C. albicans with zone of inhibition, 26.67 mm.Inspec keywords: nanomedicine, antibacterial activity, X‐ray chemical analysis, nanoparticles, transmission electron microscopy, particle size, infrared spectra, microorganisms, X‐ray diffraction, Fourier transform spectra, ultraviolet spectra, scanning electron microscopy, visible spectra, nanofabricationOther keywords: green biosynthesis, antimicrobial activities, silver nanoparticles, green synthesis, physical methods, study reports, solanum viarum fruit, ultraviolet‐visible spectrophotometer analysis, high microbial activity, highest antimicrobial activity, s. viarum fruit, transmission electron microscopy, energy dispersive X‐ray spectroscopy image     

Phyto‐mediated synthesis,biological and catalytic activity studies of gold nanoparticles

In the present study, a phyto‐mediated synthesis of gold nanoparticles (AuNPs) using an isoflavone, Dalspinosin (5,7‐dihydroxy‐6,3′,4′‐trimethoxy isoflavone) isolated from the alcoholic extract of roots of Dalbergia coromandeliana is reported. It is observed that Dalspinosin itself acts both as a reducing and a capping agent in the synthesis of the nanoparticles (NPs). An ultraviolet–visible (UV–Vis) spectral study showed a surface plasmon resonance band at 526 nm confirming the formation of AuNPs. The NPs formed were characterised by UV–Vis spectroscopy, Fourier transform‐infrared spectroscopy, X‐ray diffraction (XRD), high‐resolution transmission electron microscopy (HR‐TEM) with energy‐dispersive x‐ray spectroscopy (EDX) and dynamic light scattering. HR‐TEM analysis showed the synthesised AuNPs were spherical in shape with a size of 7.5 nm. The AuNPs were found to be stable for seven months when tested by in vitro methods showed good antioxidant and anti‐inflammatory activities. They also showed moderate anti‐microbial activities when tested against Gram positive (Staphylococcus aureus and Streptococcus sp), Gram negative bacterial strains (Klebsiella pneumonia and Klebsiella terrigena) and fungal strain (Candida glabrata). The biosynthesised AuNPs showed significant catalytic activity in the reduction of methylene blue with NaBH₄ to leucomethylene blue.Inspec keywords: biomedical materials, catalysis, Fourier transform infrared spectra, gold, light scattering, microorganisms, nanomedicine, nanoparticles, spectrochemical analysis, surface plasmon resonance, transmission electron microscopy, ultraviolet spectra, visible spectra, X‐ray chemical analysis, X‐ray diffractionOther keywords: phyto‐mediated synthesis, biological activity studies, catalytic activity studies, dalspinosin (5,7‐dihydroxy‐6,3′,4′‐trimethoxy isoflavone), alcoholic extract, roots, Dalbergia coromandeliana, ultraviolet‐visible spectral study, surface plasmon resonance band, UV‐Vis spectroscopy, Fourier transform‐infrared spectroscopy, X‐ray diffraction, high‐resolution transmission electron microscopy, EDX analysis, dynamic light scattering, HR‐TEM analysis, antioxidant activities, antiinflammatory activities, antimicrobial activities, Gram positive bacterial strains, Staphylococcus aureus, Streptococcus sp, Gram negative bacterial strains, wavelength 526 nm, size 7.5 nm, time 7 month, Au     

Role of Ribes khorassanicum in the biosynthesis of AgNPs and their antibacterial properties

Silver nanoparticles (AgNPs) have been biosynthesised through the extracts of Ribes khorassanicum fruits, which served as the reducing agents and capping agents. Biosynthesised AgNPs have been found to be ultraviolet–visible (UV–vis) absorption spectra since they have displayed one surface plasmon resonance peak at 438 nm, attesting the formation of spherical NPs. These particles have been characterised by UV–vis, field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy analysis. The formation of AgNPs at 1.0 mM concentration of AgNO₃ has resulted in NPs that contained mean diameters in a range of 20–40 nm. The green‐synthesised AgNPs have demonstrated high antibacterial effect against pathogenic bacteria (i.e. Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa). Biosynthesising metal NPs through plant extracts can serve as the facile and eco‐friendly alternative for chemical and/or physical methods that are utilised for large‐scale nanometal fabrication in various medical and industrial applications.Inspec keywords: X‐ray diffraction, X‐ray chemical analysis, nanofabrication, surface plasmon resonance, nanoparticles, antibacterial activity, microorganisms, scanning electron microscopy, silver, nanomedicine, visible spectra, ultraviolet spectra, transmission electron microscopy, Fourier transform infrared spectra, field emission scanning electron microscopy, biomedical materialsOther keywords: antibacterial properties, silver nanoparticles, reducing agents, capping agents, surface plasmon resonance peak, spherical NPs, field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, transmission electron microscopy analysis, plant extracts, ultraviolet‐visible absorption spectra, Fourier transform infrared spectroscopy, antibacterial effect, Ribes khorassanicum fruits, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, surface plasmon resonance, AgNO₃ , Ag     

Antibacterial activity of carbon nanoparticles isolated from chimney soot

Carbon nanoparticles (CNPs) are isolated from chimney soot and characterised by various tools such as X‐ray diffraction, scanning electron microscopy, transmission electron microscopy and ultraviolet–visible spectroscopy. The X‐ray diffraction studies confirm the presence of C₆₀ nanoparticles in the isolated sample. The thermal properties of the prepared CNPs are recorded using thermogravimetric analysis and differential thermal analysis. The analysis of the antibacterial activity of the synthesised CNPs against selected Gram‐positive and Gram‐negative bacterial strains is also investigated. The systematic study confirms that CNPs collected from chimney soot exhibit good antibacterial potency against Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, and Proteus mirabilis.Inspec keywords: ultraviolet spectra, scanning electron microscopy, visible spectra, differential thermal analysis, thermal analysis, antibacterial activity, nanoparticles, X‐ray diffraction, nanofabrication, transmission electron microscopy, carbonOther keywords: chimney soot, transmission electron microscopy, ultraviolet–visible spectroscopy, thermal properties, thermogravimetric analysis, differential thermal analysis, antibacterial activity, carbon nanoparticles, X‐ray diffraction study, gram‐positive bacterial strains, gram‐negative bacterial strains, antibacterial potency, scanning electron microscopy, C₆₀      

Inhibitory effect of TiO2 NPs on symbiotic arbuscular mycorrhizal fungi in plant roots

While nanoparticles (NPs) are known to exhibit antimicrobial properties, their effects on symbiotic arbuscular mycorrhizal fungi (AMF) in plant roots has to be carefully examined as NPs particularly of titanium dioxide (TiO₂) reach plant roots through varied sources such as fertilisers, plant protection products and other nanoproducts. The objective of the present study is to assess the effect of TiO₂ NPs on the symbiotic behaviour of AMF colonising rice (Oryza sativa L.) plants. Using sol–gel method, TiO₂ NPs with three different sizes were successfully synthesised employing doping. Characterisation of the prepared material was done by X‐ray powder diffraction and scanning electron microscopy. The synthesised materials were applied at 0, 25, 50 and 100 mg plant–1 to the rhizosphere of mycorrhizal rice plants maintained in pots. The study revealed that the prepared NPs had an inhibitory effect on arbuscular mycorrhizal symbiosis in plant roots. Development of AMF structures such as vesicles and arbuscules was significantly reduced in TiO₂ ‐doped NPs with a relatively more inhibition in 2% TiO₂ ‐doped NPs. Among the concentrations of TiO₂ NPs applied to different treatments, %F was significantly (P < 0.001) affected at medium to higher levels of application.Inspec keywords: nanoparticles, titanium compounds, antibacterial activity, sol‐gel processing, X‐ray diffraction, scanning electron microscopy, microorganisms, cellular biophysics, nanomedicineOther keywords: symbiotic arbuscular mycorrhizal fungi, plant roots, nanoparticles, antimicrobial properties, fertilisers, plant protection, nanoproducts, AMF colonising rice, sol‐gel method, X‐ray powder diffraction, scanning electron microscopy, mycorrhizal rice plants, rhizosphere, arbuscular mycorrhizal symbiosis, soil biota, TiO₂      

Green synthesis of copper oxide nanoparticles using aqueous extract of Convolvulus percicus L. as reusable catalysts in cross‐ coupling reactions and their antibacterial activity

CuO nanoparticles (NPs) were prepared by Convolvulus percicus leaves extract as a reducing and stabilising agent. The green synthesised copper oxide NPs was characterised by transmission electron microscope, energy dispersive X‐Ray spectroscopy, X‐ray diffraction, Fourier transform infrared and ultraviolet‐visible analysis. The activities of the CuO NPs as catalyst were tested in the formation of C‐N and C‐O bonds. The N ‐arylated and O ‐arylated products of amides, N‐H heterocycles and phenols were obtained in excellent yields. Furthermore, the separation and recovery of copper oxide NPs was very simple, effective and economical. The recovered catalyst can be reused several times without significant loss of its catalytic activity. Moreover, the antibacterial activity of these NPs was tested against two human pathogenic microbes and showed significant antimicrobial activity against these pathogenic bacteria.Inspec keywords: copper compounds, nanoparticles, nanomedicine, antibacterial activity, biomedical materials, nanofabrication, microorganisms, catalysts, transmission electron microscopy, X‐ray chemical analysis, X‐ray diffraction, Fourier transform spectra, infrared spectra, ultraviolet spectra, visible spectra, catalysisOther keywords: green synthesis, copper oxide nanoparticles, Convolvulus percicus L. aqueous extract, reusable catalysts, cross‐coupling reactions, antibacterial activity, reducing agent, stabilising agent, transmission electron microscope, energy dispersive X‐ray spectroscopy, X‐ray diffraction, Fourier transform infrared spectra, ultraviolet‐visible spectra, C‐N bonds, C‐O bonds, N‐arylated products, O‐arylated products, amides, N‐H heterocycles, phenols, catalytic activity, human pathogenic microbes, antimicrobial activity, CuO     

Structural and physicochemical properties of Rheum emodi mediated Mg(OH)2 nanoparticles and their antibacterial and cytotoxic potential

In the present investigation, Rheum emodi roots extract mediated magnesium hydroxide nanoparticles [Mg(OH)₂ NPs] through the bio‐inspired experimental technique were synthesised. Mg(OH)₂ NPs were characterised by using various characterisation techniques such as field emission scanning electron microscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible spectroscopy. The formation of Mg(OH)₂ NPs was confirmed by X‐ray diffraction. The structural analysis confirmed the hexagonal crystal symmetry of Mg(OH)₂ NPs with space group P‐3m1 and space group no. 164 using the Rietveld refinement technique. TEM micrographs illustrated the nano‐size formation of Mg(OH)₂ NPs of spherical shape and size ∼14.86 nm. With the aid of FTIR data, plant metabolites such as anthraquinones have been identified as a stabilising and reducing agent for the synthesis of biogenic Mg(OH)₂ NPs. The synthesised Mg(OH)₂ NPs showed antimicrobial and cytotoxic potential against Gram‐negative and Gram‐positive bacteria such as Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) and MDA‐MB‐231 human breast cancer cell lines.Inspec keywords: antibacterial activity, microorganisms, visible spectra, cancer, X‐ray diffraction, cellular biophysics, nanomedicine, ultraviolet spectra, nanoparticles, transmission electron microscopy, nanofabrication, field emission scanning electron microscopy, Fourier transform infrared spectra, particle size, magnesium compounds, space groups, toxicologyOther keywords: physicochemical properties, structural properties, Rheum emodi root extract mediated magnesium hydroxide nanoparticles, bio‐inspired experimental technique, field emission scanning electron microscopy, transmission electron microscopy, TEM, Fourier transform infrared spectroscopy, FTIR spectroscopy, ultraviolet‐visible spectroscopy, X‐ray diffraction, hexagonal crystal symmetry, space group P‐3m1, space group no. 164, Rietveld refinement technique, nanosize formation, plant metabolites, spherical shape, antibacterial potential, cytotoxic potential, reducing agent, anthraquinones, stabilising agent, Gram‐positive bacteria, Gram‐negative bacteria, Escherichia coli, Staphylococcus aureus, MDA‐MB‐231 human breast cancer cell lines, Mg(OH)₂      

Green synthesis of silver nanoparticles with the Arial part of Dorema ammoniacum D. extract by antimicrobial analysis

Silver nanoparticles (SNPs) were synthesised by using the Arial part extract of Dorema ammoniacum D. and characterised by employing UV–visible spectroscopy, Fourier transform infrared spectroscopy and X‐ray diffraction techniques. Transmission electron microscopy and field emission scanning electron microscopy were applied to investigate the morphological structure of the bio‐synthesised SNPs. The antimicrobial activity of SNPs was studied against Gram positive (Bacillus cereus and Staphylococcus aureus) and Gram‐negative (Escherichia coli and Salmonella typhimurium) bacteria by employing the disk diffusion agar process. An extremely antimicrobial effect was observed for SNPs. Utilising D. ammoniacum D. as a mediator for the synthesis of SNPs helped to save time and cost.Inspec keywords: silver, nanoparticles, nanofabrication, nanomedicine, biomedical materials, particle size, antibacterial activity, visible spectra, ultraviolet spectra, microorganisms, field emission scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, surface diffusionOther keywords: green synthesis, silver nanoparticles, Dorema ammoniacum D. extract, antimicrobial analysis, Arial part extract, UV‐visible spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, morphological structure, bio‐synthesised SNPs, antimicrobial activity, gram positive Bacillus cereus bacteria, gram positive Staphylococcus aureus bacteria, gram‐negative Escherichia coli bacteria, gram‐negative Salmonella typhimurium bacteria, disk diffusion agar process, antimicrobial effect, Ag     

Biogenic fabrication of CuNPs,Cu bioconjugates and in vitro assessment of antimicrobial and antioxidant activity

In the present study, the authors synthesised copper nanoparticles (CuNPs) by using extract of Zingiber officinale (ginger) and later the NPs were bioconjugated with nisin, which shows antimicrobial activity against food spoilage microorganisms. CuNPs and its bioconjugate were characterised by ultraviolet–vis spectroscopy, NP tracking analysis, Zetasizer, transmission electron microscopy analysis, X‐ray diffraction and Fourier transform infra‐red (FTIR) spectroscopy. Zeta potential of CuNPs and its bioconjugate were found to be very stable. They evaluated in vitro efficacy of CuNPs and its bioconjugate against selected food spoilage bacteria: namely, Staphylococcus aureus, Pseudomonas fluorescens, Listeria monocytogenes and fungi including Fusarium moniliforme and Aspergillus niger. Antimicrobial activity of CuNPs was found to be maximum against F. moniliforme (18 mm) and the least activity was noted against L. monocytogenes (13 mm). Antioxidant activity of CuNPs and ginger extract was performed by various methods such as total antioxidant capacity reducing power assay, 1‐1‐diphenyl‐2‐picryl‐hydrazyl free radical scavenging assay and hydrogen peroxide assay. Antioxidant activity of CuNPs was higher as compared with ginger extract. Hence, CuNPs and its bioconjugate can be used against food spoilage microorganisms.Inspec keywords: antibacterial activity, biomedical materials, copper, nanoparticles, nanofabrication, nanomedicine, microorganisms, ultraviolet spectra, visible spectra, electrokinetic effects, transmission electron microscopy, X‐ray diffraction, Fourier transform infrared spectra, free radical reactions, food technologyOther keywords: biogenic fabrication, Cu bioconjugates, in vitro assessment, antimicrobial activity, antioxidant activity, copper nanoparticles, Zingiber officinale, ultraviolet‐visible spectroscopy, NP tracking analysis, Zetasizer, transmission electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, FTIR, zeta‐potential, food spoilage bacteria, Staphylococcus aureus, Pseudomonas fluorescens, Listeria monocytogenes, fungi, Fusarium moniliforme, Aspergillus niger, F. moniliforme, L. monocytogenes, ginger extract, total antioxidant capacity, power assay, 1‐1‐diphenyl‐2‐picryl‐hydrazyl free radical scavenging assay, hydrogen peroxide assay, food spoilage microorganisms, Cu     

Evaluation of antimicrobial activity of synthesised silver nanoparticles using Thymus kotschyanus aqueous extract

Development of a green chemistry process for the synthesis of silver nanoparticles (AgNPs) has become a focus of interest. Characteristics of AgNPs were determined using techniques, such as ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy and X‐ray diffraction (XRD). The synthesised AgNPs using Thymus kotschyanus had the most growth inhibition against gram‐positive bacteria such as Staphylococcus aureus and Bacillus subtilise, while the growth inhibition of AgNPs at 1000–500 µg/ml occurred against Klebsiella pneumonia and at 1000–250 µg/ml of AgNPs was observed against E. coli. The UV–vis absorption spectra confirmed the formation of the AgNPs with the characteristic peak at 415 nm and SEM micrograph acknowledged spherical particles in a nanosize range. FTIR measured the possible biomolecules that are responsible for stabilisation of AgNPs. XRD analysis exhibited the crystalline nature of AgNPs and showed face‐centred cubic structure. The synthesised AgNPs revealed significant antibacterial activity against gram‐positive bacteria.Inspec keywords: visible spectra, microorganisms, ultraviolet spectra, biomedical materials, nanofabrication, nanoparticles, X‐ray diffraction, scanning electron microscopy, molecular biophysics, X‐ray chemical analysis, nanomedicine, silver, antibacterial activity, Fourier transform infrared spectraOther keywords: green chemistry process, ultraviolet–visible spectroscopy, gram‐positive bacteria, silver nanoparticles, Thymus kotschyanus aqueous extract, UV–vis spectroscopy, Fourier transform infrared spectroscopy, FTIR analysis, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, SEM micrograph, X‐ray diffraction, XRD, Staphylococcus aureus, Bacillus subtilise, Klebsiella pneumonia, E. coli, UV–vis absorption spectra, face‐centred cubic structure, antibacterial activity, antimicrobial activity, wavelength 415.0 nm, Ag     

Antibacterial,anticancer and antioxidant potential of silver nanoparticles engineered using Trigonella foenum‐graecum seed extract

In this study, the authors report a simple and eco‐friendly method for the synthesis of silver nanoparticles (AgNPs) using Trigonella foenum‐graecum (TFG) seed extract. They explored several parameters dictating the biosynthesis of TFG‐AgNPs such as reaction time, temperature, concentration of AgNO₃, and TFG extract amount. Physicochemical characterisation of TFG‐AgNPs was done on dynamic light scattering (DLS), field emission electron microscopy, energy dispersive X‐ray spectroscopy, X‐ray diffraction and Fourier transform infrared spectroscopy. The size determination studies using DLS revealed of TFG‐AgNPs size between 95 and 110 nm. The antibacterial activity was studied against Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa and Staphylococcus aureus. The biosynthesised TFG‐AgNPs showed remarkable anticancer efficacy against skin cancer cell line, A431 and also exhibited significant antioxidant efficacy.Inspec keywords: antibacterial activity, cancer, biomedical materials, silver, nanofabrication, nanomedicine, nanoparticles, microorganisms, skin, cellular biophysics, biochemistry, light scattering, X‐ray chemical analysis, X‐ray diffraction, Fourier transform infrared spectra, particle sizeOther keywords: antibacterial potential, anticancer potential, antioxidant potential, silver nanoparticles, Trigonella foenum‐graecum seed extract, eco‐friendly method, biosynthesis, reaction time, AgNO₃ concentration, TFG extract amount, physicochemical characterisation, dynamic light scattering, field emission electron microscopy, energy dispersive X‐ray spectroscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, size determination, TFG‐AgNPs size, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus aureus, skin cancer cell line A431, Ag     

Biocompatibility enhancement of graphene oxide‐silver nanocomposite by functionalisation with polyvinylpyrrolidone

Several materials such as silver are used to enhance graphene oxide (GO) sheets antimicrobial activity. However, these toxic materials decrease its biocompatibility and hinder its usage in many biological applications. Therefore, there is an urgent need to develop nanocomposites that can preserve both the antimicrobial activity and biocompatibility simultaneously. This work highlights the importance of functionalisation of GO sheets using Polyvinylpyrrolidone (PVP) and decorating them with silver nanoparticles (AgNPs) in order to enhance their antimicrobial activity and biocompatibility at the same time. The structural and morphological characterisations were performed by UV‐Visible, Fourier transform infrared (FTIR), and Raman spectroscopic techniques, X‐ray diffraction (XRD), and high‐resolution transmission electron microscopy (HR‐TEM). The antimicrobial activities of the prepared samples against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans were studied. The cytotoxicity of prepared materials was tested against BJ1 normal skin fibroblasts. The results indicated that the decoration with AgNPs showed a significant increase in the antimicrobial activity of GO and FGO sheets, and functionalisation of GO sheets and GO‐Ag nanocomposite with PVP improved the cell viability about 40 and 35%, respectively.Inspec keywords: biomedical materials, nanocomposites, visible spectra, ultraviolet spectra, X‐ray diffraction, cellular biophysics, nanoparticles, Raman spectra, filled polymers, transmission electron microscopy, silver, microorganisms, antibacterial activity, nanomedicine, nanofabrication, graphene compounds, toxicology, Fourier transform infrared spectraOther keywords: graphene oxide‐silver nanocomposite, polyvinylpyrrolidone, toxic materials, biocompatibility, antimicrobial activity, morphological characterisations, structural characterisations, UV‐visible spectra, Fourier transform infrared spectra, Raman spectra, X‐ray diffraction, high‐resolution transmission electron microscopy, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, cytotoxicity, BJ1 normal skin fibroblasts, cell viability, CO‐Ag     

Biogenic synthesis of Au,Ag and Au–Ag alloy nanoparticles using Cannabis sativa leaf extract

Biogenic synthesis of gold (Au), silver (Ag) and bimetallic alloy Au–Ag nanoparticles (NPs) from aqueous solutions using Cannabis sativa as reducing and stabilising agent has been presented in this report. Formation of NPs was monitored using UV–visible spectroscopy. Morphology of the synthesised metallic and bimetallic NPs was investigated using X‐ray diffraction and scanning electron microscopy. Elemental composition and the surface chemical state of NPs were confirmed by energy dispersive X‐ray spectroscopy analysis. Fourier transform‐infrared spectroscopy was utilised to identify the possible biomolecules responsible for the reduction and stabilisation of the NPs. Biological applicability of biosynthesised NPs was tested against five bacterial strains namely Klebsiella pneumonia, Bacillus subtilis (B. subtilis), Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa (P. aeruginosa) and Leishmania major promastigotes. The results showed considerable antibacterial and anti‐leishmanial activity. The Au–Ag bimetallic NPs showed improved antibacterial activity against B. subtilis and P. aeruginosa as compared to Au and Ag alone, while maximum anti‐leishmanial activity was observed at 250 μg ml⁻¹ NP concentration. These results suggest that biosynthesised NPs can be used as potent antibiotic and anti‐leishmanial agents.Inspec keywords: silver, silver alloys, gold, gold alloys, nanoparticles, nanofabrication, reduction (chemical), ultraviolet spectra, visible spectra, X‐ray diffraction, scanning electron microscopy, X‐ray chemical analysis, Fourier transform infrared spectra, microorganisms, antibacterial activityOther keywords: biogenic synthesis, Cannabis sativa leaf extract, bimetallic alloy Au–Ag nanoparticles, aqueous solutions, reducing agent, stabilising agent, UV–visible spectroscopy, X‐ray diffraction, scanning electron microscopy, elemental composition, surface chemical state, energy dispersive X‐ray spectroscopy analysis, Fourier transform‐infrared spectroscopy, biomolecules, bacterial strains, Klebsiella pneumonia, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Leishmania major promastigotes, antibacterial activity, anti‐leishmanial activity, Ag, Au, AuAg     

Green synthesis of titanium dioxide nanoparticles with volatile oil of Eugenia caryophyllata for enhanced antimicrobial activities

Different chemo‐physical methods are used to synthesise titanium oxide nanoparticles (TiO₂ NPs), which are often expensive, unfriendly to the environment, toxic, not biocompatible, with a small yield. To resolve these problems, the researchers use green procedures to synthesise TiO₂ ‐NPs by plant extracts of Capsicum annum L. and Allium cepa (onion) and characterise using atomic force microscopy, scanning electron microscopy, transmission electronic microscopy, X‐ray diffraction, ultraviolet (UV)–visible (Vis) spectra and Fourier transform infrared spectroscopy. The results indicate that most NPs synthesised by the first and second procedures of onion had an average diameter of 95.7 and 89.1 nm, while NPs synthesised by C. annum had an average diameter of 103.60 and 90.07 nm, respectively. In UV–Vis spectra, strong absorption was below 470 nm, and energy gap was 3.3 eV in each of the first procedure of A. cepa and the second procedure of C. annum compared with 270 nm, 6.3 eV for each of the second procedure of A. cepa and the first procedure of C. annum. The antimicrobial activities of NPs were evaluated and an attempt was made to enhance these activities by Eugenia caryophyllata plant''s oil in combination therapies. There were synergistic effects between NPs and plant''s oil.Inspec keywords: scanning electron microscopy, visible spectra, nanofabrication, titanium compounds, ultraviolet spectra, X‐ray diffraction, nanoparticles, atomic force microscopy, antibacterial activity, transmission electron microscopy, Fourier transform infrared spectra, nanomedicine, semiconductor materials, semiconductor growthOther keywords: cepa, green synthesis, titanium dioxide nanoparticles, volatile oil, eugenia caryophyllata, capsicum annum, atomic force microscopy, electron microscopy, transmission electronic microscopy, UV‐visible spectra, plant extracts, antimicrobial activities, chemophysical methods, Capsicum annum L., Allium cepa, scanning electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, onion, plant oil, TiO₂      

Biosynthesis of Ag3 PO4 nanoparticles in the absence of phosphate source using a phosphorus mineralising bacterium

Silver phosphate nanoparticles were biologically synthesised, for the first time, using a dilute silver nitrate solution as the silver ion supplier, and without any source of phosphate ion. The applied bacterium was Sporosarcina pasteurii formerly known as Bacillus pasteurii which is capable of solubilising phosphate from soils. It was speculated that the microbe accumulated phosphate from the organic source during the growth period, and then released it to deionised water. According to the transmission electron microscopy images and X‐ray diffraction results, the produced nanoparticles were around 20 nm in size and identified as silver phosphate nanocrystals. The outcomes were also approved by energy‐dispersive X‐ray analysis, thermogravimetric and differential scanning calorimetry analyses, ultraviolet–visible spectroscopy, and Fourier transform infrared spectroscopy analysis. Finally, the antibacterial effect of the obtained nanoparticles was verified by testing them against Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium. The activity of silver phosphate nanoparticles against gram‐negative strains was better than the gram positives. It should be mentioned that the concentrations of 500 and 1000 mg/l were found to be strongly inhibitory for all of the strains.Inspec keywords: nanoparticles, silver compounds, nanofabrication, microorganisms, antibacterial activity, transmission electron microscopy, X‐ray diffraction, X‐ray chemical analysis, differential scanning calorimetry, ultraviolet spectra, visible spectra, Fourier transform infrared spectraOther keywords: biosynthesis, phosphate source, phosphorus mineralising bacterium, silver phosphate nanoparticles, Sporosarcina pasteurii, Bacillus pasteurii, deionised water, transmission electron microscopy images, X‐ray diffraction, energy‐dispersive X‐ray analysis, thermogravimetric analyses, differential scanning calorimetry analyses, ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, antibacterial effect, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Ag₃ PO₄      

Catalytic reduction of 2,4‐dinitrophenylhydrazine by cuttlebone supported Pd NPs prepared using Conium maculatum leaf extract

A facile and green process to synthesise cuttlebone supported palladium nanoparticles (Pd NPs/cuttlebone) is reported using Conium maculatum leaf extract and in the absence of chemical solvents and hazardous materials. The antioxidant content of the C. maculatum leaf extract played a significant role in converting Pd²⁺ ions to Pd NPs. Various techniques were used for the characterisation of the Pd NPs/cuttlebone such as field‐emission scanning electron microscopy, X‐ray diffraction, energy dispersive X‐ray spectroscopy, Fourier transform infrared and ultraviolet–visible spectroscopy. This Pd NPs/cuttlebone showed excellent catalytic activity in the reduction of 2,4‐dinitrophenylhydrazine to 2,4‐diaminophenylhydrazine by sodium borohydride as the source of hydrogen at ambient condition. The catalyst could be separated and recycled up to five cycles with no loss of its activity.Inspec keywords: catalysis, catalysts, chemical engineering, palladium, nanoparticles, field emission electron microscopy, scanning electron microscopy, X‐ray diffraction, X‐ray chemical analysis, sodium compounds, ultraviolet spectroscopy, visible spectroscopyOther keywords: catalytic reduction, 2,4‐dinitrophenylhydrazine, cuttlebone, Conium maculatum leaf extract, green process, palladium nanoparticles, antioxidant content, field‐emission scanning electron microscopy, X‐ray diffraction, energy dispersive X‐ray spectroscopy, Fourier transform infrared, ultraviolet–visible spectroscopy, 2,4‐diaminophenylhydrazine, sodium borohydride     

Removal of toxic contaminants from water by sustainable green synthesised non‐toxic silver nanoparticles

The study describes the synthesis of silver nanoparticles using 21 different plant extracts having medicinal properties. Molecular ultraviolet‐visible spectroscopy shows that the λ _max of nanoparticles synthesised by different plant extracts varied and ranged between 400 and 468 nm. The ultraviolet results revealed that although synthesis of nanoparticles occurred by all plant extracts successfully, their size varies, this was further confirmed by differential light scattering. The synthesised nanoparticles were investigated for their antimicrobial properties. The most promising silver nanoparticles Ocimum sanctum and Artemisia annua assisted were further characterised using transmission electron microscopy and energy dispersive X‐ray spectroscopy (EDX). EDX data confirms that synthesised nanoparticles are highly pure. Further these two plant assisted nanoparticles were studied for chemocatalytic and adsorptive properties. The silver nanoparticles from Ocimum sanctum can catalyse the reduction of 4‐nitrophenol (63%) within 20 min in the presence of NaBH₄, whereas Artemisia annua assisted silver nanoparticles did not show significant chemocatalytic activity. Both the promising nanoparticles can efficiently adsorb textile dyes from aqueous solutions. These synthesised nanoparticles were also exploited to remove microbial and other contaminants from Yamuna River water. The nanoparticles show excellent antimicrobial properties and can be reused repeatedly.Inspec keywords: antibacterial activity, nanofabrication, silver, dyes, light scattering, visible spectra, microorganisms, X‐ray diffraction, transmission electron microscopy, X‐ray chemical analysis, catalysis, nanoparticles, ultraviolet spectra, adsorption, reduction (chemical)Other keywords: sustainable green synthesised nontoxic silver nanoparticles, silver nitrate, molecular ultraviolet–visible spectroscopy, plant assisted nanoparticles, plant extracts, Ocimum sanctum, Artemisia annua, E. coli, C. albicans, plasmon absorbance, differential light scattering, energy dispersive X‐ray spectroscopy, 4‐nitrophenol, chemocatalytic activity, Yamuna River water, antimicrobial properties, time 20.0 min, time 5.0 min to 240.0 hour, size 1.0 nm to 5.0 nm, size 5.0 nm to 20.0 nm, wavelength 400.0 nm to 468.0 nm, NaBH₄ , Ag     

Antibiofilm and antimicrobial efficacy evaluation of polypyrrole nanotubes embedded in aminated gum acacia based nanocomposite

The sustainable development of natural polysaccharide‐based hybrid composites is highly important for the effective replacement of metal nanoparticles in diverse applications. Here, polypyrrole nanotubes (PPyNTs) were embedded on the surface of aminated gum acacia (AGA) to produce ecofriendly nanocomposites for biomedical applications. The morphology of a PPyNT‐enhanced AGA (PPyNT@AGA) hybrid nanocomposite was studied by scanning electron microscopy and transmission electron microscopy and their affirmed interactions were characterised by X‐ray diffraction, Raman, Fourier transform‐infrared and UV‐visible spectroscopy. Interestingly, the prepared PPyNT@AGA nanocomposite exhibited 90% biofilm inhibition against gram‐negative Pseudomonas aeruginosa, gram‐positive Streptococcus pneumoniae and fungal strain Candida albicans with promising antimicrobial performance. This study establishes the good inhibition of a PPyNT@AGA hybrid composite against various microorganisms. The stability of the nanocomposite coupled with antimicrobial activity enables an effective strategy for diagnosing and controlling pathogens.